Bolt-anchor.



H. W. PLHSUER.

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2 SHEETS-SHEET y @if Wi @5 H. w. PLEISTER.

BOLT ANCHOR.

APFLICATON FILED JAN-20.19?. Lilh Patented Nov. 27, 191'?.

2 SHEETS-SHEET 2.

narran ,eras rarniar cierren HENRY W. PLEISTER, 0F WESTFIELD, NEVI JERSEY, ASSIG-NOR T0 HENRY B. NEWI-IALL.

BOLT-ANCHOR.

Specification of Letters Patent.

Application filed January 20, 1917. Serial No. 143,423.

To all whom t may concern:

Be it known that I,"IIENRY W. PLEISTER, a citizen of the United States,`residing at Westfield, in the county `of Union and State of New Jersey, have invented certain new and useful Improvements in Bolt-Anchors, of which the following is aV specification, taken in connection with the accompanying drawings.

My'invention relates to bolt anchors.

More particularly my present invention relates to that class of bolt anchors known as anchors, lead anchors and screw anchors, in which the material of the anchor is formed of more or less ductile material such as an alloy of lead, in which a wood screw will cut its own cooperating female threads. Such anchors are used to hold lighter work than are lag shields. f

In the present form of anchors the maximum expansion `is approximately at the extreme inner end ofthe anchor'. In practice this is often a serious detriment in that the wood screw having forced the'V anchor out to its maximum expansion binds and it is impossible to bring the head of the wood screw up flush with the work. This' requires the hole to be enlargedY entailing additional labor and expense, or a diiferent size anchor has to be used.

By my invention I'overcome this serious objection and give a longer surface of maximum contact or grip on the exterior of the anchor, thereby giving an increased frictional hold, and distributing this maximum grip over a larger area than with the present form of anchors. My invention further permits the wood screw to coperate with the anchor with less effort than with the present forms. 1

In my present invention I provide the interior of the anchor with longitudinally extending ribs or surfaces which irst'engage and guide the screw as it is screwed home. The wood screw cuts its own coperating screwthreads in these ribs or surfaces, and generally, though not necessarily, cuts entirely through the ribs into the body of the anchor.

I further employ an anchor in which the interior bore of the body of the anchor is inclined substantially uniformly from near one endto the other, in which case I provide it with interior ribs or surfaces of varying height, preferably being inclined from near one end to a point intermediate the ends of the anchor where the inclination of the ribs reach the nearest approach to the axis, and from that point they continue parallel, preferably to theV end of the anchor. In this form the desirable result above pointed out is obtained with theminimum amount of metal.

Or I may employ an anchor having a body formed with an axial bore, a portion of the bore being inclined from near one end to a point intermediatethe ends of the anchor, and from that point merging-into a substantially cylindrical surface, the inclined and cylindrical bore being provided with internal ribs.

My invention further-relates to certain details of construction which will be described in the specification and pointed out in the claims.`

I have shown in the accompanying drawings, different illustrative embodiments of my invention but of course it is to be understood that my invention is not to be confined simply to the forms 4illustrated except as required by the scope of the accompanying claims. In these drawings the same reference numerals refer to similar parts.

Figure l is a longitudinal vertical section of one form of my improved anchor in which the body of the lead anchor has a uniformly tapering surface beginning substantially at one end and continuing to the other end and provided with inclined ribs of varying height reaching the nearest approach to the axis at a pointintermediate the endsv of the anchor;

Fig. 2 is a tvertical section of the lead anchor shown in Fig. l mounted in a support and cooperating with a wood screw;

F ig. 3 is a plan view of the lead anchor shownin F ig. l;

Fig. 4t is a transverse vertical section substantially on the line lr-4 of Fig. l, looking inthe direction of the arrows;

Patented Nov.. 2*?, IWL Tf..

Fig. 5 is a transverse vertical section substantially on the line 5 5 of Fig. 1, looking in the direction of the arrows;

Fig-6 is a longitudinalvertical section of a modified form of my invention in which the body of the anchor is provided with an internal 2inclined..surface extending from near one end to a point intermediate the length of the anchor and there merging-into a cylindrical surface, the said internal inclined and cylindrical surfaces ofthe 'anchor being provided with longitudinally.extending ribs of substantially the same Vheight throughout f their length v Fig. V'i' is a vertical section of the bolt anchor shown `in Fig.A 6 located within a wallor other support and cooperating with ga .wood screw;

Eig-Sis a plan viewofthe anchorshown in Fig. 6;

. Fig. v9is a transverseverticalsection substantially'on the line 9-9 of Fig. G, looking in the i direction. of the arrows;

Fig. 10 -is a transverse vertical section .substantially on the line l10--10 of Fig. 6, looking in the direction of the arrows;

-11 isa further modification in which .theribsare provided only upon the interior inclined surface of the anchor.

Inthe illustrative.embodiments of my invention .1, Fig. .1, is an 4anchor having a .collar-2 and tines 3 and 1. rIhis anchor has a body portion 5 `which has an interior inclined surface G of substantially uniform 4taper fromtheiend 7 to the innerend 8.

-In Lsuch `an anchor, ,if .the i screwthreads `9 :oftheywoodscrew 10 are made-to cut their own coperating screwthreads directly in 4this lunigform tapering .surface i 6, the Amaximum expansion ofthe anchor will beat points equivalentto I11, 111. `This has-many objections for the reasons hereinafter more fully pointed lfout.

I,therefore, in .this form of my ,invent-ion, provide the uniformly tapering surface (3 of the ;body member 5 with Va rib or ribs 12,5.of varying thickness, In the preferred construction, illustrated iirFigs 1 to 5 in- Y elusive, 4I lise 4a plurality of 1these Linterior lribs 512 which are inclined fromV approximately-.the point l13, reaching the nearest 14,11. From these 4points `the ribs continue `of the .same

fheight Iorgthickness forming parallel .ribs

and an interrupted cylindrical engaging surface for the woodmscrew 10, from the -points 14,14 tothe end 8, even though the bodywportion of theanchor may be tapering as illustrated :in Fig. 1.

These ribs 12, 12 serve the function of -not onlyI 'guiding the entering screw 10 but `also Aforming ansiengalging suuface @having a relatively steep ,incline ,which terminates at a point which is nearest the axis and intermediate the ends of the anchor and from that ,equivalentto the -f-ace of contact and increased frictional hold and distributing the maximum grip over a Vlarger-area than in the old form .of `lead anchors now on the market. forms employ a uniformly tapering axial bore in which the maximnmrgrip 1is at the extreme inner end ofgthe :anchoratpoints equivalent to the `points* 111,11. V p

Not only is it easier toposition the wood screw 10 and to obtain a stronger and-more lastingV grip uponQthe wall of the; hole 15, but when the support 16 happens tofbe material which may `be damaged, as `for example a thin slab of marble or plaster, or any other sion.or grip 4being distributedover a larger area prevents anyv damage of the support v16. In Fig. 2 I .have shown .the work 1S of a: certainthickness held to the face 19 ofthe V20 ofthe wood screw tobe brought up flush with the work without'the screw amming in the anchor ina position whereits head 20 cannot be brought snuglyagainst the work. This 'is dueto the fact `that the ,point of maximum;expansionis extended over a relatively large surfaceof the anchor, so that `the-end of the` screw V.10.can be brought any- '.where along that `,portion 21, 21 of ithe ,ribs 12, 12 which runparallel to each other, or past the endof the anchor as .may be 4found necessaryto bring `.the .head 1S flush against the work and at the same timeobtain 4the `requisite maximnmexpansion of the anchor. In the vold form, V,where the maximumex- `pansion is atthe endof the anchor, at points points 11, 1l, the screw would often Vjam at .this point before its head could be brought flush with the work 18,- whatever its 'thickness .may be, requiring .or thickness .as in Fig. 1 to permit them to .approach fthe axis,` a considerable .saving in metal is obtained. Y

Insomecases, as for lexample inFfig 6,

I may use an anchor 2&1 having a body portion 25, which body portion is provided with These old material, thermaximum expanvan inclined surface 26 extending fromone their length. In this form the points 28, 28

which are nearest to the axis are formed by the body portion 25 itself rather than in the first form, that illustrated in Figs. 1 to 5 inclusive, wherein the point of nearest approach to the axis is formed by varying the depth of the ribs. In the present form, that shown in Fig. 6, the ribs 30 serve to guide the entering wood screw 31 and permit its easy passage into the anchor, its male threads 32, cutting their own coperating female threads in the ribs 30, and usually in the body 25 of the anchor. It is of course to be understood that the depth of the screwthreads cut by the screw depends upon the relative size of the anchor and the screw, the size of the hole and of the weight of the work or load 33.

l/Vhen this anchor is placed in a hole 34 of the support 35 its tines 36, 36 will be expanded in the same manner as that previously described, the maximum expansion being distributed over comparatively a wide portion of the wall 37 of the hole lying between the points 38, 38 and 39, 39, though this distance may be varied as desired.

In some cases I may provide a bolt anchor 40 Fig. 11, having the body member 41 provided with an inclined interior surface 42 reaching the nearest approach to the axis at 43, 43, and there merging into the cylindrical surface 44. From the end 45 to the points 43, 43, I provide longitudinally extending internal ribs 46, 46, which in this particular form, terminate at the points 43 43.

ljreferably the combined thickness of the wall of the anchor and the ribs is least at the outer end of the anchor, said combined thickness increasing to a maximum at a point intermediate the ends of the anchor and then continuing at a substantially uniform combined thickness to the other end of the anchor. y

It will be further noted that preferably the aperture or bore left between the points of the ribs reaches its minimum diameter at a point between the ends of the anchor, and then merge into a cylindrical ribbed aperture or bore.

It will be seen that when the expanding means coperate with the axial bore, said bore is distorted into a substantially true cylindrical bore, thereby distorting the forward exterior cylindrical surface of the bolt anchor into a frustum of a cone, which merges into the cylindrical exterior of the outer end of the bolt anchor.

1 `In the different figures of the drawings, for purpose of illustration, I have somewhat exaggerated the preferred angle of the inclined portion of the axial bore.

Having thus described this invention in connection with several illustrative embodiments thereof, to the details of which I do not desire to be limited, what is claimed as new and what is desired to secure by Letters Patent is set forth in the appended claims:

l. An article of manufacture comprising a ductile anchor having an axial opening provided with ribs whose edges are inclined from the outer end of the anchor to a point intermediate its ends, and which edges are in a cylindrical surface from said point to the opposite end of the anchor.

2. An article of manufacture comprising a ductile anchor having an internal bore with inclined ribbed surface, the aperture left between the points of the ribs reaching its minimum diameter between the ends of the anchor and merging into a cylindrical ribbed bore.

3. An article of manufacture comprising a ductile anchor having an internal ribbed surface, the ribs varying in height to vary the cross-section of the axial bore.

4. An article of manufacture comprising a ductile anchor having internal ribs inclined from near one end to a point removed from the other end of the anchor and there merging into a cylindrical bore.

5. An article of manufacture comprising a ductile anchor having internal ribs inclined from near one end to a point removed from the other end of the anchor and then merging into parallel ribs.

6. An article of manufacture comprising a ductile anchor having an inclined substantially uniform interior tapering bore extending from near one end to the other and provided with interior ribs of varying height to vary the pitch of the bore.

7. An article of manufacture comprising a ductile anchor having an inclined substantially uniform interior tapering bore extending from near one end to the other and provided with interior ribs inclined from near one end to a point intermediate the ends of the anchor and parallel from that point to the other end of the anchor.

8. An article of manufacture comprising a ductile anchor in the form of a hollow cylinder provided with ribs on its tapered interior bore, the combined thickness of the wall and the ribs being least at its outer end, said combined thickness increasing to a maximum at a point intermediate the ends and thence continuing at a substantially unifordlm combined thickness to the opposite en 9. An article ofmanufaeture eompifising 'endoffthe:anchoraarustumfofa uCone and a ductile anehor'cylndreal.inexterior prorattheinnerend oftheanchoi a cylinder. vided with an interior bore taperedthroughf v Y a .out itsl length, said bore provided With a HENRY W. PLEISTER.` plurality of ribs, each rib varying in height Vitnesses: y Y i Y at different points, the aperture left between M. 1R. RYAN, `the points of .the `ribs formingatthe outer A. M. WILLIAMS.

Copies-of this patent may be obtained Vflor liveeentsneachfbyl addressing ntlie" Comiss'ioneret latenti,

Washington, 1L C. 

